Occasionally my 86 TPI iroc would crank a lot before starting, put a gauge on it and noticed it wasn’t holding fuel pressure, I decided to do the pump and sending unit, swapped in a AC Delco Pump and Spectra premium sending unit, unfortunately it didn’t fix my hard start problems, I started to get SES Code 54, I swapped in a new relay to no avail, then I started smelling raw gas at the charcoal canister and I was building pressure in the tank so I put a new vent valve on the canister and replaced the one under the car near the pump, went to go start the car and it would not start at all, decided to do my injectors, EGR and FPR, now it will start but won’t stay running and it will run like ****, I put my gauge on it and it would jump up to 45-50 LBS and quickly drop down to 20 and progressively continue dropping, so Im preparing to drop the tank (Again) and replace the pump and sending unit, Any Opinions on brands to go with? I’ve been sitting on a NOS Pump and Sending Unit but weary of putting 30 Year Old NOS parts on, I occasionally do roadtrips with the car, I was planning on doing a 8 Hour - 400 ish mile round trip at the end of the summer


basically an end to this long winded post, recommendations of Pump and sending unit Brands, I don’t want to do this again for a long time!

is it a bad idea to use a NOS GM Fuel Pump and Sending Unit? (New in the original box)

could I be missing something?

Could the pressure building up in the tank have harmed the fuel pump? ( whoosh/vacuum sound when you take the gas cap off) and smell of raw gas/ bubbling near charcoal canister and under car

 

When you replaced the fuel pump the first time is it possible you got the fuel return and vacuum canister lines mixed up? Verify them first before you go putting another new pump in as 45-50 psi is a good reading.